The Research Of Synchronizing Process Of Preheating And Welding For High Strength Steel

Preheating is necessary in the welding process of high strength steel. Today, the way of artificial flame preheating is adopted widely. This procedure requires that the operators have better operative experiences, and has some defects such as low work-efficiency , bad working circumstances for workers, waste of heat and so on. Considering these factors, the defects above may be improved and the quality of welding may be promoted by developing a set of equipment which can realize the synchronization of preheating process and welding process.Firstly, a heat conducting model in the welding process of flat board surfacing was established by the theoretical analysis of temperature field computing. Then, a test platform, which can model the synchronizing process of preheating and welding, was mainly constructed with IR temperature element, the 3-axis motion platform and the relative programs for temperature measuring and motion platform controlling. The IR temperature element can be utilized to testing the temperature without contact. The 3-axis motion platform was utilized to model the moving of welding and the opening-closing of flame. And lots of tests have been done on the test platform to model the synchronizing process of preheating and welding. Using ANSYS and Gauss heat source model, the distribution of temperature field in the synchronizing process of preheating and welding was evaluated; A dynamically controlling way was proposed which controlled preheating-source to open and close depending on the temperature of the preheating-source center point; The APDL command flows were programmed to complete the evaluations and make heat sources move; Considering different dimension boards and different demands to preheating width, some simulating evaluations were done on the condition of single preheat-source and double preheat-source. By analyzing the results of evaluations above, the feasibility of processing the preheating and welding automatically at the same time was proved in theory. What we have done established the theoretical and testing base for the development of equipment tomorrow.